Dr Parker, from James Cook University’s School of Veterinary and Biomedical Sciences, and collaborator Professor Rocky de Nys, from JCU’s School of Marine and Tropical Biology, have just received a $7,000 Collaboration Across Boundaries grant to prove their theory that feeding seaweed to cow will improve their digestion and make them produce less methane.

Just like carbon dioxide, methane is a so called green-house gas and the world’s cattle population accounts for up to 20% of methane emissions from human-related activities. Global warming is suspected to be one of several factors harming our tropical reefs worldwide and finding ways of reducing the amount of methane released into the air is therefore highly interesting.

Dr Parker and Professor Rocky de Nys will now test their theory on herd of cattle living at the University’s Townsville campus.

“Orkney sheep are ruminants that live off seaweed and they do very well on such a diet; so the obvious question is, why can’t cows?” said Dr Parker.

“I like to call it the reef and beef project because it has far reaching implications that come full circle:starting with seaweed, taking in the beef and aquaculture industries, and extending back out to the sea to help conserve the Great Barrier Reef.”

A moray eel species native to warm tropical waters have been caught in the considerably colder waters found off the coast of Cornwall, UK. (picture here)

After catching the 4 feet (120 cm) long fish, West Penwith fishermen brought it to the Newlyn Fish Market auction where it was purchased by fish dealer John Payne of Marisco Fish in Penzance.

”I thought it shouldn’t be there, realised it was rare and it shouldn’t be swimming in these waters so I decided to buy it. It is a one off and first of its kind found in these waters”, said Payne who plans to stuff the eel and keep it in his shop.

Rory Goodall of Cornwall Wildlife Trust has never heard of a tropical moray eel being caught this far north before. “They are not rare in the Mediterranean but I have never heard of them being seen here so it’s possible that they have never been caught in the British waters before”, he said.

Moray eel of the species Gymnothorax meleagris.
Copyright www.jjphoto.dk.

“The ‘underwater turbulence’ the jellies create is being debated as a major player in ocean energy budgets,” says marine scientist John Dabiri of the California Institute of Technology.

Jellyfish are often seen to be aimless aquatic drifters, propelled by nothing but haphazard currents and waves, but the truth is that these gooey creatures continuously contract and relax their bells to move in desired directions.

The jellyfish Mastigias papua carries algae-like zooxanthellae within its tissues from which it derives energy and since the zooxanthellae depend on photosynthesis, the jellyfish has to stay in sunny locations. Research carried out in the so called Jellyfish Lake, located in the island nation of Palau 550 miles east of the Philippines, shows that this jellyfish doesn’t rely on currents to bring it to sunny spots – it willingly budges through the lake as the sun moves across the sky.

In Jellyfish Lake, enormous congregations of Mastigias papua can be found in the western half of the lake each morning, eagerly awaiting dawn. As the sun rises in the east, all jellyfish turn towards it and starts swimming towards east. The smarmy creatures will swim for several hours until they draw near the eastern end of the lake. They will however never reach the eastern shore, since the shadows cast by trees growing along the shoreline cause them to stop swimming. They shun the shadows and will therefore come to a halt in the now sundrenched eastern part of the lake. As the solar cycle reverses later in the afternoon, millions of jellyfish will leave the eastern part of the lake and commence their journey back to the western shore.

Together with his research partner, marine scientists Michael Dawson of the University of California at Merced, John Dabiri have investigated how this daily migration of millions of jellyfish affects the ecosystem of the lake.

What the jellies are doing, says Dabiri, is “biomixing”. As they swim, their body motion efficiently churns the waters and nutrients of the lake.

Dabiri and Dawson are exploring whether biomixing could be responsible for an important part of how ocean, sea and lake waters form so called eddies. Eddies are circular currents responsible for bringing nitrogen, carbon and other elements from one part of a water body to another. The two researchers have already shown how Jellyfish like Mastigias papua and the moon jelly Aurelia aurita use body motion to generate water flow that transports small copepods within jellyfish feeding range; now they want to see if jellyfish movements make any impact on a larger scale.

“Biomixing may be a form of ‘ecosystem engineering’ by jellyfish, and a major contributor to carbon sequestration, especially in semi-enclosed coastal waters,” says Dawson.

According to the simplest version of the so called Iron Hypothesis, plankton blooms move atmospheric carbon down to the deep sea and increased carbon dioxide levels in the atmosphere can therefore be counteracted by promoting plankton blooms. The Iron Hypothesis derives its names from the suggestion that global warming can be thwarted by fertilizing plankton with iron in regions that are iron-poor but rich in other nutrients like nitrogen, silicon, and phosphorus, such as the Southern Ocean.

New research from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory is now dealing a powerful blow to this hypothesis by showing that most of the carbon used for plankton blooms never reaches to deep sea.

Using data collected around the clock for over a year by deep-diving Carbon Explorer floats, Oceanographers Jim Bishop* and Todd Wood** have revealed that a lot of the carbon tied up by plankton blooms never sink very far.

“Just adding iron to the ocean hasn’t been demonstrated as a good plan for storing atmospheric carbon,” says Bishop. “What counts is the carbon that reaches the deep sea, and a lot of the carbon tied up in plankton blooms appear not to sink very fast or very far.”

The reasons behind this behaviour are complex, but the seasonal feeding behaviour of planktonic animal life is believed to play major part.

Photoplankton

The Carbon Explorer floats used in the study were launched in January 2002, as a part of the Southern Ocean Iron Experiment (SOFeX)***, and experiment meant to test the Iron Hypothesis in the waters between New Zealand and Antarctica during the Antarctic summer.

SOFeX fertilized and measured two regions of ocean, one in an HNLC (high-nutrient, low-chlorophyl) region at latitude 55 degrees south and another at 66 degrees south. Carbon Explorers were launched at both these sites while a third Carbon Explorer was launched well outside the iron-fertilized region at 55 degrees south as a control.

Bishop and Wood were originally assigned to the project to monitor the iron-fertilization experiment for 60 days, but the Carbon Explorers continued to transmit data throughout the Antarctic fall and winter and on into the following spring.

“We would never have made these surprising observations if the autonomous Carbon Explorer floats hadn’t been recording data 24 hours a day, seven days a week, at depths down to 800 meters or more, for over a year after the experiment’s original iron signature had disappeared,” Bishop explains. “Assumptions about the biological pump – the way ocean life circulates carbon – are mostly based on averaging measurements that have been made from ships, at intervals widely separated in time. Cost, not to mention the environment, would have made continuous ship-based observations impossible in this case. Luckily one Carbon Explorer float costs only about as much as a single day of ship time.”

The scientific hypothesis that iron can be used to stimulate phytoplankton growth in regions low in iron but rich in other nutrients is still intact and experiments show that algal blooms do in fact occur if you add iron to such waters. The study by Bishop and Wood only shows that the carbon bound by the plankton do not end up far down in the depths of the sea.

Jim Bishop’s team. (From left) Christopher Guay,
Phoebe Lam, Jim Bishop, Todd Wood, and David Kaszuba.

During the early stages of the South Sea experiment, the Iron Hypothesis seemed to hold up to scrutiny as the Berkeley researchers could detect not only a vigorous plankton bloom in the fertilized region at 55°N, but also how carbon particles sank beneath the bloom carrying 10-20 percent of the fixed carbon away from the surface layer and down to a dept of at least 100 meters. These results were published in the 2004April issue of Science.

But since the Carbon Explorers continued to submit information even when the 3-month study was officially over, Bishop and Wood could continue their monitoring of South Sea carbon levels throughout fall and winter and well into the following spring; a continued monitoring that would prove invaluable.

The two Carbon Explorers released at 55 degrees south continued to report for over 14 months and almost reached South America before they turned silent. After this, the explorer launched at 66 degrees south continued to transmit for another four months, despite having spent much of the Arctic winter recording at a dept of 800 meters where the pressure is immense. This explorer also had several encounters with the underside of chunky sea ice as it tried to surface to report during the Arctic winter.

All this new data surprisingly showed that there seemed to be much less particulate matter reaching the depth where the biomass was highest, i.e. in plankton blooms. Reports from the 66°S explorer showed how particulate carbon levels decreased sharply as the perpetually dark Arctic winter commenced and ice began to cover previously open waters. As the sun returned in spring and melted the ice the levels made a modest increase, but no sinking (sedimentation) of large amounts of carbon to the deep ocean was observed.

Another even more surprising report came from the control float, dubbed 55 C, which reported higher sedimentation of carbon 800 meters under a region with no plankton bloom than what the other 55°S (dubbed 55A) reported from the fertilized, blooming region.

Researchers are currently pondering several ideas as to explain these unforeseen results but have not reached any conclusion. A higher biomass seems to be linked to a lower export of carbon, but one knows why. One of the most promising hypotheses takes into account how phytoplankton needs sufficient amounts of light to survive and grow. Latitude 55°S is located far enough from the Arctic for light to reach the ocean year round, even though the amount is severely reduced during the winter months. But the notorious winter storms occurring in these waters can cause mixing between near-surface water and underlying water layers all the way down to a dept of 400-500 meters. Phytoplankton are dragged down to depths where it is too dark for them to grow and where hungry zooplankton waits for them.

“Mixing is the dumbwaiter that brings food down,” says Bishop. “The question is whether the dumbwaiter is empty or full.”

If mixing is consistently below the critical light level, phytoplankton can not grow, i.e. the dumbwaiter stays empty and the zooplankton gets no food. As the winter storms stop with the advent of spring, the phytoplankton can quickly rebound, aided by increased levels of sunlight. But since a lot of zooplankton starved to death during the winter, the zooplankton population is not large enough to keep steps with the phytoplankton bloom and intercept carbon loaded material as it sinks between 100 and 800 meters.

In the part of the South Sea where Carbon Explorer 55C spent the winter collecting data, storms where not continuous and the mixing was therefore halted now and then. More zooplankton survived, zooplankton which fed on the phytoplankton in spring, keeping their numbers down and increasing carbon sedimentation.

Bishop says these observations point to an important lesson: “Iron is not the only factor that

determines phytoplankton growth in HNLC regions. Light, mixing, and hungry zooplankton are fundamentally as important as iron.”

You can find more information about Bishop and Wood’s study in the journal Global Biogeochemical Cycles. Preprints of the issue are already available to subscribers at http://www.agu.org/journals/gb/papersinpress.shtml.

* Jim Bishop is a member of Berkeley Lab’s Earth Sciences Division and a professor of Earth and planetary sciences at the University of California at Berkeley.

** Todd Wood is a staff researcher with the U.S. Department of Energy’s Laurence Berkley National Laboratory.

*** The Southern Ocean Iron Experiment (SOFeX) is a collaboration led by scientists from Moss Landing Marine Laboratory and the Monterey Bay Aquarium Research Institute.

In a study announced today by the Wildlife Conservation Society* (WCS) at the International Coral Reef Initiative** (ICRI) meeting in Thailand, researchers show that some coral reefs located off East Africa are unusually resilient to climate change. The high resilience is believed to be caused by geophysical factors in combination with improved fisheries management in these waters.

After studying corals off the coast of Tanzania, researchers found that these coral reefs has made an incredibly speedy recovery from the 1998 bleaching event that wiped out up to 45 percent of the region’s corals. The authors of the study attribute the swift recovery to a combination of reef structure and reef management.

Compared to many other coral reefs around the world, Tanzania’s reefs are used to considerable variations in both current and water temperature which has turned these reefs into an unusually complex web of different coral species. This bio-diverse ecosystem includes several different species known to quickly re-colonize an area after a bleaching incident.

The authors of the study believe that reefs in other parts of the world subjected to similarly diverse environmental conditions might have the same high ability to recover from large-scale climatic and human disturbances. The study provides additional evidence that such “super reefs” can be found in the triangle from Northern Madagascar across to northern Mozambique to southern Kenya and the authors suggest that these reefs should be a high priority for conservation efforts since they may come to play an important global role in the future recovery of coral reefs worldwide.

“Northern Tanzania’s reefs have exhibited considerable resilience and in some cases improvements in reef conditions despite heavy pressure from climate change impacts and overfishing,” says Dr. Tim McClanahan***, the study’s lead author. “This gives cause for considerably more optimism that developing countries, such as Tanzania, can effectively manage their reefs in the face of climate change.”

The study also stresses the impact of direct management measures in Tanzania, including closures to commercial fishing. Algae is known to easily smother corals, but researchers found how areas with fishery closures contained a rich profusion of algae eating fish species that kept the corals clean. The few sites without any management measures remained degraded, and in one of them the population of sea urchins had exploded. Sea urchins feed on corals and can therefore worsen the problem for an already suffering reef.

The study has been published in the online journal Aquatic Conservation: Marine and Freshwater Ecosystems.

Authors of the study include Tim McClanahan and Nyawira Muthiga of the Wildlife Conservation Society, Joseph Maina of the Coral Reef Conservation Project, Albogast Kamukuru of the University of Dar es Salaam’s Department of Fisheries Science and Aquaculture, and Saleh A.S. Yahna of the University of Dar es Salaam’s Institute of Marine Sciences and Stockholm University’s Department of Zoology.

* The Wildlife Conservation Society is an institutional partner to ICRI and is actively conserving tropical coral reef species in priority seascapes in Belize, Indonesia, Papua New Guinea, Fiji, Kenya and Madagascar. Along with monitoring reefs, WCS also trains of park staff in protected areas.

** The International Coral Reef Initiative (ICRI) is a global partnership among governments and organizations working to stop and reverse the degradation of coral reefs and related ecosystems. This ICRI General Meeting was convened by the joint Mexico – United States Secretariat.

*** Dr. McClanahan’s research regarding ecology, fisheries, climate change effects, and management of coral reefs at key sites throughout the world is supported by the Western Indian Ocean Marine Science Association (WIOMSA) and The Tiffany & Co. Foundation.

Good news from Queensland: Certain reefs in Australia’s Great Barrier Reef Marine Park seem to have undergone a remarkable recovery since the devastating Keppel Islands coral bleaching event of 2006.

In 2006, massive and severe coral bleaching occurred around the Keppel Islands due to high sea temperatures. After being bleached, the reefs rapidly became overgrown with a species of seaweed and scientists feared this would be the end of the corals.

Picture is not from Keppel Island. It is another part of the Great barrier reef

Earlier studies have indicated that reefs that do manage to recover from catastrophes like this one need at least a decade or two to bounce back. However, a lucky combination of three previously underestimated ecological mechanisms now seems to have made it possible for the Keppel Islands reefs to make an amazing recovery, with large numbers of corals re-establishing themselves within a single year.

“Three factors were critical,” says Dr Guillermo Diaz-Pulido, from the Centre for Marine Studies at The University of Queensland and the ARC Centre of Excellence for Coral Reef Studies (CoECRS). “The first was exceptionally high regrowth of fragments of surviving coral tissue. The second was an unusual seasonal dieback in the seaweeds, and the third was the presence of a highly competitive coral species, which was able to outgrow the seaweed.“

Dr Diaz-Pulido also stresses that the astonishing recovery took place in a well-protected marine area where the water quality is at least moderately good.

Surviving tissue, not sexual reproduction

“The exceptional aspect was that corals recovered by rapidly regrowing from surviving tissue,” explains Dr Sophie Dove, also from CoECRS and The University of Queensland. “Recovery of corals is usually thought to depend on sexual reproduction and the settlement and growth of new corals arriving from other reefs. This study demonstrates that for fast-growing coral species asexual reproduction is a vital component of reef resilience.”

Buying time

According to Professor Ove Hoegh-Guldberg, also of the CoECRS and The University of Queensland, understanding the different mechanisms of resilience will be critical for reef management under climate change. “Clearly, we need to urgently deal with the problem of rising carbon dioxide in the atmosphere, but managing reefs to reduce the impact of local factors can buy important time while we do this. Our study suggests that managing local stresses that affect reefs, such as overfishing and declining water quality, can have a big influence on the trajectory of reefs under rapid global change.”

Dr Laurence McCook from the Great Barrier Reef Marine Park Authority agrees. “As climate change and other human impacts intensify, we need to do everything we possibly can to protect the resilience of coral reefs. This combination of circumstances provided a lucky escape for the coral reefs in Keppel Islands, but is also a clear warning for the Great Barrier Reef.“

You can find out more about the remarkable recovery in the paper “Doom and boom on a resilient reef: Climate change, algal overgrowth and coral recovery”, published in the journal PLoS ONE, by Guillermo Diaz-Pulido, Laurence J. McCook, Sophie Dove, Ray Berkelmans, George Roff, David I. Kline, Scarla Weeks, Richard D. Evans, David H. Williamson and Ove Hoegh-Guldberg.

The hydrothermal vents that line the mid-ocean ridges are a major source of iron for the creatures living in the sea. Humans are not the only ones who suffer when iron becomes scarce; creatures such as phytoplankton are known to grow listless in waters low in iron, even if they are drifting around in an environment rich in many other types of nutrients.

Earlier, scientists assumed that the iron exuded from hydrothermal vents immediately formed mineralized particles as soon as it came in contact with the salty water – a form of iron that is hard to utilize for living creatures.

New research has however unveiled that some of the iron spewed out from these vents actually remain in a form that is easy to absorb for oceanic beings. According to researcher Brandy Toner, a surprising interaction between iron and carbon in hydrothermal vents serves to stop the corrosion.

“Iron doesn’t behave as we had expected in hydrothermal plumes. Part of the iron from the hydrothermal fluid sticks to particulate organic matter and seems to be protected from oxidation processes,” Toner explains.

The research was carried out on hydrothermal vent particles collected by the team from the Tica vent in the Eastern Pacific Rise. With the help of the Advanced Light Source synchrotron at the Lawrence Berkeley National Laboratory, Toner was able to analyze the particles using focused X-ray beams.

Iron is a key player in this newly discovered process in the ocean, but the exact mechanisms remains unknown.

“So the question becomes, what are those organic compounds? Are they organic compounds like in oils and tars or is it actually the stuff of life?”, says Chris German, co-author of the paper. “Brandy’s work doesn’t mean that these [carbon-iron] complexes are definitely alive. But, this is a possible smoking gun. This paper opens up a whole new line of research and asks a new set of questions that people didn’t know they should be worrying about until now. A bit of work on a tiny nanometer scale can force you to ask questions of global significance.

Perhaps hydrothermal venting, a process traditionally believed to be a completely inorganic process, actually is a part of the organic carbon cycle on our planet.

The paper “Preservation of iron (II) by carbon-rich matrices in a hydrothermal plume” by Brandy Toner and her colleagues[1] has been published in Nature Geoscience[2].

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Aquarium Toplist function added

Zoology Prof. Yossi Loya at the Tel Aviv University in Israel has discovered that corals changes sex to survive periods of stress, such as high water temperatures. By observing the behaviour of Japanese sea corals he discovered that stressed female mushroom coral (fungiid coral) change gender to become males, and that male corals are much better at handling stress and fare better at surviving on limited resources. Not all females go through his change but many do and most of the population is therefore male during periods of intense stress.

Yossi Loya says: “We believe, as with orchids and some trees, sex change in corals increases their overall fitness, reinforcing the important role of reproductive plasticity in determining their evolutionary success. One of the evolutionary strategies that some corals use to survive seems to be their ability to change from female to male, As males, they can pass through the bad years, then, when circumstances become more favourable, change back to overt females. Being a female takes more energy, males are less expensive to maintain. They are cheaper in terms of their gonads and the energy needed to maintain their bodies. Having the ability to change gender periodically enables a species to maximize its reproductive effort.”

Loya’s discoveries have been published in the Proceedings of the Royal Society B. The professor hopes that this new knowledge will help coral farmers by allowing them to reproduce the hardy Fungiid corals more effectively.

Loya has been studying coral reefs for more than 35 years and won the prestigious Darwin Medal for a lifetime contribution to the study of coral reefs. He is also involved in coral rehabilitation projects in the Red Sea and is a professor at the Tel Aviv University in Israel.

The oceans of the world absorb a large part of the carbon dioxide released into the atmosphere by us burning fossil fuels, burning forests to make room for fields, etc. This have helped slow down global warming, but new studies shows that it might have a devastating effects on certain fish species such as clown fish. Tests performed on clown fish larvae have shown that increased levels of carbon dioxide can make them disoriented an unable to find a suitable home and avoid predators. The pH level in the ocean has dropped 0.1 since pre-industrial times due to the absorption of carbon dioxide and researchers believe that it will fall another 0.3-0.4 before the end of this century.

This increased acidicy of the water can cause serious problems for clown fish larvae, since clownfish larvae lose the ability to sense vital odours in more acidic waters – probably owing to the damage caused to their olfactory systems. Kjell Døving (Oslo University), co-author of the rapport that was published in US journal Proceedings of the National Academy of Sciences, says “They can’t distinguish between their own parents and other fish, and they become attracted to substances they previously avoided. It means the larvae will have less opportunity to find the right habitat, which could be devastating for their populations.“

The research indicates that other species might be affected in a similar way and might have a hard time finding their way to suitable habitats if carbon dioxide levels raises in the oceans.

About the study

The study was executed in such a way that the researchers checked how well clownfish larvae could detect smells in normal sea water (pH 8.15) and how well they could detect odours in more acidic water (at levels predicted to be a reality around the year 2100 and later). The test showed that at pH 7.8 the larvae stopped following scent trails released by reefs and anemones and started following sent trails they would normally avoid; scents that are associated with environments not suitable for clown fish. The larvae also lost the ability to use smell to distinguish between their parents and other fish. At pH 7.6 the larvae were unable to follow any kind of odour in the water, and instead swam in random directions.

Wild-caught pets are often recommended against, since the harvest of wild caught specimen may deplete wild populations. In the Brazilian rainforest, the harvesting of popular aquarium species such as cardinal tetras have however helped prevent deforestation and made it possible for local residents to earn a living without resorting to logging, mining, cattle ranching, and slash-and-burn agriculture.

“All this is very counter-intuitive,” says Scott Dowd, an Amazon biologist at the New England Aquarium who has been researching the dark acidic waters of Rio Negro, a major Amazon tributary in Northern Brazil, for the past two decades. “You would think biologists would not want to take fish out of the rainforest. But the fish are the key to miminizing deforestation. The people’s other economic options – timber harvest, cattle ranching and gold mining – are environmental disasters.”
The Rio Negro region has been a major fish exporter for over half a century and 60 percent of local populations rely in this source of income for their sustenance. Since deforestation is known to be detrimental to the survival of financially valuable fish species like the cardinal tetra fish, the Brazilian government has protected the Rio Negro rainforest from logging and burning – at least until now. The situation may be about to change dramatically as more and more aquarium shops switch from wild-caught fish to farm-raised specimens. Wild-caught specimens are used to the dark, soft and highly acidic water conditions of Rio Negro, while farm-raised fish tend to be acclimatized to common tap-water conditions (i.e. clear water that is not very soft or acidic) and therefore easier to keep.

To prevent the market for wild-caught Rio Negro fish from collapsing, Dowd is participating in a “Buy a Fish, Save a Tree” campaign. “The local fisheries look like they are headed for collapse”, Down explains. “But there’s hope that this threat can be addressed. If you ask fish hobbyists if they care about the environment, a very high percentage say they care about it deeply.”

Dowd hopes that the “Buy a Fish, Save a Tree” branding will help Brazilian fish harvesters to benefit from the growing trend of cause labelling, such as Fair Trade and FSC (Forest Stewardship Council).

Another important step in making wild-caught Rio Negro fish a popular alternative to farmed-raised specimens is to adapt them to normal aquarium conditions, and the New England Aquarium is therefore helping local fishermen to efficiently acclimatize wild-caught tetras to a pH-value around 7.0.

Dowd also hope to take advantage of the Internet, by assigning lot numbers to every batch of aquarium fish caught in Rio Negro. “Imagine if you could go online and see a video of the actual fisherman who caught your tropical fish, says Dowd. “I want hobbyists to know directly how their choices can affect people thousands of miles away and how they can make a contribution to saving the rainforest. Things don’t look good, but we can begin to turn all of this around.”